To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘Beyond 4G Network’ or a ‘Post LTE System’. The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems. In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like. In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.
The Internet, which is a human centered connectivity network where humans generate and consume information, is now evolving to the Internet of Things (IoT) where distributed entities, such as things, exchange and process information without human intervention. The Internet of Everything (IoE), which is a combination of the IoT technology and the Big Data processing technology through connection with a cloud server, has emerged. As technology elements, such as “sensing technology”, “wired/wireless communication and network infrastructure”, “service interface technology”, and “Security technology” have been demanded for IoT implementation, a sensor network, a Machine-to-Machine (M2M) communication, Machine Type Communication (MTC), and so forth have been recently researched. Such an IoT environment may provide intelligent Internet technology services that create a new value to human life by collecting and analyzing data generated among connected things. IoT may be applied to a variety of fields including smart home, smart building, smart city, smart car or connected cars, smart grid, health care, smart appliances and advanced medical services through convergence and combination between existing Information Technology (IT) and various industrial applications.
In line with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as a sensor network, Machine Type Communication (MTC), and Machine-to-Machine (M2M) communication may be implemented by beamforming, MIMO, and array antennas. Application of a cloud Radio Access Network (RAN) as the above-described Big Data processing technology may also be considered to be as an example of convergence between the 5G technology and the IoT technology.
Recently, wireless communication technology has been suddenly developed, and thus communication system technology has repeatedly evolved. Among them, a system that has currently been highlighted as 4th generation (4G) mobile communication technology is a long term evolution (LTE) system. In the LTE system, in order to satisfy the traffic command that is suddenly increasing, various technologies have been introduced, and one of such technologies is carrier aggregation (CA). In the related art, only one carrier is used to perform communications between a terminal (user equipment (UE), hereinafter referred to as a “terminal”) and a base station (E-UTRAN NodeB or eNB, hereinafter referred to as a “base station”). The CA technology is a technology that additionally uses a primary carrier and one or more secondary carriers, and thus can greatly increase throughput based on the number of secondary carriers being added.
In the LTE system, a cell in a base station that uses a primary carrier is called a primary cell (PCell), and a cell in a base station that uses a secondary cell is called a secondary cell (SCell). Only one PCell exists, and 4 SCells (based on LTE Release 11) can exist at maximum. However, the number of SCells can be further increased in the future.
The LTE system may be a system that performs communications using a licensed band frequency that a communication service provider is allocated with from the Government. Recently, in order to satisfy the traffic demand that is suddenly increasing, technology for using LTE technology in an unlicensed band that is currently used by wireless local area network (LAN) or Bluetooth (BT) has been defined, and such usage of the LTE technology in the unlicensed band is called licensed assisted access (LAA) technology. In the case of grafting the CA technology on the LAA technology, a scenario in which the PCell uses a licensed band frequency and the SCell uses an unlicensed band frequency through the LAA technology may be considered. The SCell that uses the unlicensed band as described above may be called an unlicensed SCell (U-SCell).
On the other hand, the latest terminal, such as a smart phone, may perform communications using a different wireless communication system (e.g., wireless LAN technology) that uses the unlicensed band in addition to an LAA wireless communication system that uses the LAA technology. For example, a user may receive a service through the unlicensed band through an access of a private wireless LAN access point (AP) at home. However, if a cell that uses the unlicensed band has been set to use a secondary carrier in a terminal, or a base station instructs the terminal to set the cell that uses the unlicensed band to use the secondary carrier in the case where the user of the terminal intends to access the private AP at home, the terminal is unable to perform communications simultaneously using the LAA wireless communication system and the different wireless communication system that uses the unlicensed band in the same unlicensed band or an adjacent unlicensed band.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.